#define _CRT_SECURE_NO_WARNINGS  1
#include <stdio.h>
int main()
{
    int n = 0, m = 0;
    int arr[10][10];
    int i = 0;
    int sum = 0;
    scanf("%d %d", &n, &m);
    for (i = 0; i < n; i++)
    {
        int j = 0;
        for (j = 0; j < m; j++)
        {
            scanf("%d", &arr[i][j]);
            if (arr[i][j] > 0)
            {
                sum += arr[i][j];
            }

        }
    }
    printf("%d ", sum);


    return 0;
}